I'm not sure how much the uniform contributes to wins but I think there is a lot to a very young team just establishing itself also being able to be the first team to wear such updated uniforms that could definitely help make them feel like a more integrated, cohesive unit that is really part of something rather than just a component added to a team. There might be a little more pride and confidence when they put on the uniform that feels more like their own, a better sense of identity, and if you feel that way, then no doubt you will bring a little more confidence, a little more swagger, and a little more investment in the way you play and the way you want to "feel it" with your teammates.
If this were a team of veterans with a history of winning, the change makes no sense, and likely has the opposite effect.
I was skeptical of the uniforms at first. I liked our previous uniforms. but next to these ones, that have grown on me immensely, the old uniforms look like low budget high school jerseys or something.